1. Field of the Invention
The invention pertains to a refractory pouring spout and channel unit for installation at the outlet of a vessel containing molten metal, especially at the outlet of the tundish of a strip casting machine, where the pouring spout and channel unit has at least one vertical, refractory pouring spout and channel part, which can be connected to the tundish, and a horizontal refractory pouring spout and channel part, which originates from the vertical part and is provided with one or more openings distributed over its length.
2. Description of the Related Art
In a known strip casting machine according to the publication FR-A-2 753,402, a distribution vessel is arranged above the casting rolls, and a ladle is arranged above the vessel. In this case a pouring spout and channel provided at the outlet of the ladle projects into the distribution vessel, which has its own outlet and nozzle directed at the gap between the casting rolls. In addition, a stopper rod is provided in the ladle to control the discharge of the molten metal. The disadvantage here is that, when the distribution vessel is full, the ferrostatic level is relatively high, which causes the discharge rate to be high as well. Thus, as a result of the molten metal flowing between the casting rolls, the quantity of molten metal flowing in is not constant, and the bath formed between the casting rolls becomes agitated to a corresponding degree.
The publication JP-A-01-228,649 (Abstract and Drawings) describes a refractory pouring spout and channel unit which is installed on a tundish and which is immersed in the molten bath located between two casting rolls. The pouring spout and channel unit consists of an outlet, which is connected to the tundish, and an immersion tube, which surrounds the outlet. The immersion tube consists of a pouring spout and channel part extending in the horizontal direction, which is provided with several openings for the molten metal distributed over its length. The immersion tube has a longitudinal chamber in its interior, and underneath the chamber there are two elongated distribution bores, which are connected to each other via openings. Slots proceed upward at a slant from the elongated bores; the molten metal arriving in the immersion tube from the outlet enters the molten metal bath between the casting rolls through these slots. The disadvantage of this pouring spout and channel unit is that, because of the selected design, the molten metal has a relatively large amount of kinetic energy as it emerges. It can be seen that the flow of molten metal is supposed to be directed toward the surface of the casting rolls, from which it is deflected into the molten metal bath, as a result of which it is possible under certain conditions for damage to occur to the cast shell of the poured strip.